1. Field of the Invention
In general, the present invention relates to the structure of pharmaceutical vials and especially the structure of caps for such vials. The present invention also relates to electronic devices that monitor the viability of the contents of a pharmaceutical vial.
2. Prior Art Description
Many pharmaceutical products are administered by injection. In many instances, the pharmaceutical product is packaged in a vial by the manufacturer. To prevent contamination of the pharmaceutical product, the vial is sealed with a piercable cap. In order to access the contents of the vial, a needle from a hypodermic syringe must be driven through the structure of the cap. Once the tip of the needle is inside the vial, the pharmaceutical product can be drawn out of the vial by the operation of the syringe.
Some vials contain enough pharmaceutical product for a single dose to a single patient. Other vials contain enough pharmaceutical products for multiple patients. Vials that contain enough pharmaceutical product for multiple patients have a cap structure that will be pieced by multiple hypodermic syringes at various times. When the needle of a hypodermic syringe pierces a cap, it creates a hole. If this hole is not closed, the hole leaves a passage for bacteria, air, and moisture to contaminate the contents of the syringe. In order to prevent such contamination, many pharmaceutical manufacturers utilize safety caps on vials that automatically reseal each time they are pierced by a needle. Such safety caps are exemplified by U.S. Pat. No. 4,815,619 to Turner, entitled Medicament Vial Safety Cap. Additionally, industry utilizes single/multiple use pre-filled syringes for pharmaceutical product distribution to patients.
Many pharmaceutical products, such as vaccines, can be compromised not only by contamination but also by variations in temperature and the passage of time. Many pharmaceutical products have a posted shelf life. If the pharmaceutical product stands unused for longer than its shelf life, the pharmaceutical product loses potency and may no longer be effective. Furthermore, many pharmaceutical products are highly sensitive to temperature. If the temperature of a pharmaceutical product is too high, molecules within the product may break down. Likewise, if a pharmaceutical product becomes too cold, emulsions may separate into component ingredients. In either case, the pharmaceutical product may be rendered useless.
In order to monitor the temperature and shelf life of pharmaceutical products, electronic devices have been created that are packaged with the pharmaceutical products. Such electronic monitoring devices are exemplified by U.S. Pat. No. 6,810,350 to Blakely, entitled Determination Of Pharmaceutical Expiration Date. Such electronic devices produce an audible alarm if the pharmaceutical product is expired or has been temperature compromised. However, such prior art electronic monitoring devices have many disadvantages. Since such prior art monitoring devices are units that are separate and distinct from the vials/prepackaged syringes that hold the pharmaceutical product, the electronic devices are often attached to the packaging of the vial/prepackaged syringes or the shipping container of the vial. Once individual vials/prepackaged syringes are removed from their shipping containers, they become separated from the electronic monitoring device. The individual vials/prepackaged syringes may then become compromised without detection. Furthermore, prior art electronic monitoring devices are battery operated. If the battery dies, the electronic monitor stops working. A person may then think that a very old vial is good. The same situation may occur if the electronic monitoring device becomes damaged during shipping or accidentally gets wet and stops working.
A need therefore exists for an improved monitoring device that monitors the age and temperature history of a pharmaceutical product in a vial/prepackaged syringe, yet cannot be separated from the pharmaceutical vial/prepackaged syringe. A need also exists for a monitoring device that prevents a compromised pharmaceutical product from being used, even if the monitoring device itself is damaged. These needs are met by the present invention as described and claimed below.